Using npm package ssh2 within an Angular2 application running under electron - node.js

Question

I want to create an Angular2 service which uses the npm package ssh2 - https://www.npmjs.com/package/ssh2.
I have installed and configured it as I would expect - the code for my service can be seen below (this code is based on the first example shown on the ssh2 npm site and github repo(the only change being I am using a password rather than a key for authentication)):
const Client = require('ssh2').Client;
const fs = require('fs');
import { NextObserver } from 'rxjs/Observer';
import { Observable } from 'rxjs/Rx';
export class SSHClient {
username: string;
password: string;
host: string;
port: number;
ssh: any;
constructor() {
}
init(username, password, host, port) {
console.log("initiating SSH connection to:" + host + "on port:" + port);
this.username = username;
this.password = password;
this.host = host;
this.port = port;
console.log("Connecting now...");
var conn = new Client();
conn.on('ready', function() {
console.log('Client :: ready');
conn.exec('uptime', function(err, stream) {
if (err) throw err;
stream.on('close', function(code, signal) {
console.log('Stream :: close :: code: ' + code + ', signal: ' + signal);
conn.end();
}).on('data', function(data) {
console.log('STDOUT: ' + data);
}).stderr.on('data', function(data) {
console.log('STDERR: ' + data);
});
});
}).connect({
host: this.host,
port: this.port,
username: this.username,
password: this.password
});
console.log("SSH Client created and demo has run");
}
}
I make my call to the service as per this from within my component:
this.ssh.init("username","password","my.little.host",22);
And I expect to get back the output of the uptime command having executed over SSH on my server - via the console. However instead of that - I get this:
EXCEPTION: Uncaught (in promise): Error: Error in ./ServerBrowserComponent class ServerBrowserComponent_Host - inline template:0:0 caused by: Cannot read property 'connect' of undefined
TypeError: Cannot read property 'connect' of undefined
at SSHClient.init (file:///Users/myapp/build/app.js:40259:12)
at new ServerBrowserComponent (file:///Users/myapp/build/app.js:34158:19)
at new Wrapper_ServerBrowserComponent (/AppModule/ServerBrowserComponent/wrapper.ngfactory.js:7:18)
at DebugAppView._View_ServerBrowserComponent_Host0.createInternal (/AppModule/ServerBrowserComponent/host.ngfactory.js:16:38)
at DebugAppView.AppView.create (file:///Users/myapp/build/app.js:27754:26)
at DebugAppView.create (file:///Users/myapp/build/app.js:27954:49)
at ComponentFactory.create (file:///Users/myapp/build/app.js:24393:41)
at ViewContainerRef_.createComponent (file:///Users/myapp/build/app.js:23441:50)
at RouterOutlet.activate (file:///Users/myapp/build/app.js:72709:45)
at ActivateRoutes.placeComponentIntoOutlet (file:///Users/myapp/build/app.js:72207:21)
ORIGINAL STACKTRACE:
Error: Uncaught (in promise): Error: Error in ./ServerBrowserComponent class ServerBrowserComponent_Host - inline template:0:0 caused by: Cannot read property 'connect' of undefined
TypeError: Cannot read property 'connect' of undefined
at SSHClient.init (ssh.service.ts:49)
at new ServerBrowserComponent (server.browser.component.ts:31)
at new Wrapper_ServerBrowserComponent (wrapper.ngfactory.js:7)
at DebugAppView._View_ServerBrowserComponent_Host0.createInternal (host.ngfactory.js:16)
at DebugAppView.AppView.create (core.umd.js:9170)
at DebugAppView.create (core.umd.js:9370)
at ComponentFactory.create (core.umd.js:5809)
at ViewContainerRef_.createComponent (core.umd.js:4857)
at RouterOutlet.activate (router.umd.js:3457)
at ActivateRoutes.placeComponentIntoOutlet (router.umd.js:2955)
at resolvePromise (zone-node.js:468)
at zone-node.js:445
at ZoneDelegate.invoke (zone-node.js:232)
at Object.onInvoke (core.umd.js:6206)
at ZoneDelegate.invoke (zone-node.js:231)
at Zone.run (zone-node.js:114)
at zone-node.js:502
at ZoneDelegate.invokeTask (zone-node.js:265)
at Object.onInvokeTask (core.umd.js:6197)
at ZoneDelegate.invokeTask (zone-node.js:264)
Unhandled Promise rejection: Error in ./ServerBrowserComponent class ServerBrowserComponent_Host - inline template:0:0 caused by: Cannot read property 'connect' of undefined ; Zone: angular ; Task: Promise.then ; Value: ViewWrappedError TypeError: Cannot read property 'connect' of undefined
at SSHClient.init (file:///Users/myapp/build/app.js:40259:12)
at new ServerBrowserComponent (file:///Users/myapp/build/app.js:34158:19)
at new Wrapper_ServerBrowserComponent (/AppModule/ServerBrowserComponent/wrapper.ngfactory.js:7:18)
at DebugAppView._View_ServerBrowserComponent_Host0.createInternal (/AppModule/ServerBrowserComponent/host.ngfactory.js:16:38)
at DebugAppView.AppView.create (file:///Users/myapp/build/app.js:27754:26)
at DebugAppView.create (file:///Users/myapp/build/app.js:27954:49)
at ComponentFactory.create (file:///Users/myapp/build/app.js:24393:41)
at ViewContainerRef_.createComponent (file:///Users/myapp/build/app.js:23441:50)
at RouterOutlet.activate (file:///Users/myapp/build/app.js:72709:45)
at ActivateRoutes.placeComponentIntoOutlet (file:///Users/myapp/build/app.js:72207:21)
Error: Uncaught (in promise): Error: Error in ./ServerBrowserComponent class ServerBrowserComponent_Host - inline template:0:0 caused by: Cannot read property 'connect' of undefined(…)
The bulk of that seems to be struggling because : Cannot read property 'connect' of undefined -- yet I am following the example documentation. Can somebody please help my understand why this is not working - and how I can fix it?
I tried to pull the code out of my project and into its own file which looks like:
const Client = require('ssh2').Client;
console.log("Connecting now...");
var conn = new Client();
conn.on('ready', function() {
console.log('Client :: ready');
conn.exec('uptime', function(err, stream) {
if (err) throw err;
stream.on('close', function(code, signal) {
console.log('Stream :: close :: code: ' + code + ', signal: ' + signal);
conn.end();
}).on('data', function(data) {
console.log('STDOUT: ' + data);
}).stderr.on('data', function(data) {
console.log('STDERR: ' + data);
});
});
}).connect({
host: 'my.little.host',
port: 22,
username: 'uname',
password: 'pwd'
});
console.log("SSH Client created and demo has run");
But I get the same error:
var conn = new Client();
^
ReferenceError: Client is not defined
at Object.<anonymous> (/Users/myapp/attempt.js:2:21)
at Module._compile (module.js:541:32)
at Object.Module._extensions..js (module.js:550:10)
at Module.load (module.js:458:32)
at tryModuleLoad (module.js:417:12)
at Function.Module._load (module.js:409:3)
at Module.runMain (module.js:575:10)
at run (node.js:348:7)
at startup (node.js:140:9)
at node.js:463:3
So something simple is going wrong here, what could it be!?

Answer 1

the ssh2-package is for node.js, not frontend/web.
The browser can't use network like that (electron uses two processes, the browser/renderer -process does not have access to the network features you need)
does your electron app have a main.js file?
that's where you need to implement the ssh functionality.
i.e. in the main-process, not in the renderer-process.
http://electron.atom.io/docs/tutorial/quick-start/#main-process

Answer 2

In my wrapper of ssh2 (ssh2shell) I have this.connection = new require('ssh2')(); within the constructor of the class or it could be put in the init function. Creating it within the instance might help.
"use strict";
class SSHClient {
constructor() {}
init(username, password, host, port) {
console.log("initiating SSH connection to:" + host + "on port:" + port);
var ssh = require('ssh2').Client
this._conn = new ssh();
console.log("Connecting");
console.log('Client :: ready');
var self = this
this._conn.on('ready', function() {
self._conn.exec('uptime', function(err, stream) {
if (err) throw err;
stream.on('data', function(data) {
console.log('STDOUT: ' + data);
}).stderr.on('data', function(data) {
console.log('STDERR: ' + data);
}).on('close', function(code, signal) {
console.log('Stream :: close :: code: ' + code + ', signal: ' + signal);
self._conn.end();
});
});
}).connect({
host: host,
port: port,
username: username,
password: password
});
console.log("SSH Client created and demo has run");
}
}
module.exports = SSHClient
Or using my package ssh2shell the ssh connection instance is within the sope of ssh2shell instance so you don't have to worry about it.
"use strict";
class SSHClient {
constructor() {}
init(username, password, host, port) {
console.log("initiating SSH connection to:" + host + "on port:" + port);
var host = {
server: {
host: host,
port: port,
userName: username,
password: password
},
commands: [ "uptime" ]
}
var SSH2Shell = require ('ssh2shell'),
//Use a callback function to handle the response text
callback = function(sessionText){
console.log("SSH Client created and demo has run");
console.log("Response:\n" + sessionText)
}
//Create a new instance passing in the host object
this._conn = new SSH2Shell(host)
//Start the process
this._conn.connect(callback);
}
}
module.exports = SSHClient